1. Technical Field of the Invention
The present invention relates to a semiconductor device (a driver IC) that drives a display device such as a LCD panel or the like.
2. Conventional Art
A conventional driver IC that drives a LCD panel is described with reference to FIGS. 3-4.
FIG. 3 shows a LCD module using a conventional semiconductor device. As shown in FIG. 3, a LCD module 40 includes a driver IC 31, a LCD panel 20 and a glass substrate 41. In other words, the driver IC 31 and the LCD panel 20 are mounted on the glass substrate 41 to form the LCD module 40.
The LCD panel 20 has a plurality of regions 101, 102, . . . in a segment direction, and a plurality of regions 301, 302, . . . in a common direction. Here, by specifying one region in the segment direction and one region in the common direction, one pixel (dot) is specified. As an example, the LCD panel 20 has 160 regions along the segment direction, and also 160 regions along the common direction. In this case, the LCD panel 20 has 160xc3x97160 pixels.
The driver IC 31 has an elongated shape in one direction, and segment signal output terminals S201-S360 of gold (Au) bumps for outputting segment signals are formed along a central section of one edge (an upper edge in the figure) in the longitudinal direction of a mounting surface thereof. Also, common signal output terminals C201-C280 and C281-C360 of gold (Au) bumps for outputting common signals are formed along sections on both sides of the central section of the one edge (the upper edge in the figure) in the longitudinal direction of the mounting surface of the driver IC 31. Furthermore, input terminals Q1-Qn of gold (Au) bumps are formed along the other edge (a lower edge in the figure) of the longitudinal direction of the mounting surface of the driver IC 31.
Transparent wirings LS201-LS360 and LC201-LC360 are formed on the glass substrate 41. The regions 101-260 of the LCD panel 20 are connected to the segment signal output terminals S201-S360 of the driver IC 31 by the wirings LS201-LS360, respectively. Also, the regions 301-380 of the LCD panel 20 are connected to the common signal output terminals C201-C280 of the driver IC 31 by the wirings LC201-LC280, respectively, and the regions 381-460 of the LCD panel 20 are connected to the common signal output terminals C360-C281 of the driver IC 31 by the wirings LC360-LC281, respectively.
FIG. 4 shows an internal structure of the driver IC 31. In FIG. 4, the driver IC 31 includes a package 32 and a silicon substrate 33 that is sealed in the package 32.
A segment signal output section 34 is formed along one edge (an upper edge in the figure) in a longitudinal direction of the silicon substrate 33. Also, common signal output sections 35-36 are formed along both of the edges in a shorter edge direction of the silicon substrate 33. Furthermore, a power supply section 37, a control section 38, and a RAM 39 are formed along the other edge (a lower edge in the figure) in the longitudinal direction of the silicon substrate 33. The segment signal output section 34, the common signal output sections 35-36, the power supply section 37, the control section 38 and the RAM 39 are mutually connected by wirings (not shown).
The segment signal output section 34 is connected to the segment signal output terminals S201-S360, and outputs segment signals through the segment signal output terminals.
The common signal output section 35 is connected to the common signal output terminals C201-C280, and outputs common signals through these common signal output terminals. The common signal output section 36 is connected to the common signal output terminals C281-C360, and outputs common signals through these common signal output terminals C281-C360.
The power supply section 37, the control section 38 and the RAM 39 are connected to the input terminals Q1-Qn, and input a power supply potential, a control signal, image data and the like through these input terminals.
The power supply section 37 receives a power supply potential from the input terminal and performs a regulation thereof, and supplies a power to the common signal output sections 35-36, the control section 38 and the RAM 39.
The control section 38 is a logical circuit, which receives a control signal through the input terminal, and controls the segment signal output section 34, the common signal output sections 35-36, the power supply section 37 and the RAM.
The RAM 39 receives image data through the input terminal and stores the same.
Referring back to FIG. 3, segment signals are successively output from the segment signal output terminals S201-S360 of the LCD driver 31 by the segment signal output section 34 described above. On the other hand, common signals are successively output from the common signal output terminals C201-C280 and C360-C281 of the LCD driver 31 by the common signal output sections 35-36 described above. Accordingly, the LCD panel 20 can be driven by the LCD driver 31.
In the conventional driver IC 31 described above, the common signal output sections 35-36 are formed along both of the edges in a short edge direction of the silicon substrate 33, as shown in FIG. 4, in order to optimize the area efficiency.
However, when the common signal output sections 35-36 are formed along both of the edges in a short edge direction of the silicon substrate 33, the length of the silicon substrate 33 in the short-edge direction cannot be shortened, and therefore the length of the driver IC 31 in its short-edge direction cannot be shortened. This causes a problem in that it is difficult to narrow a frame section of the LCD module 40 to slim down the same. This problem is particularly noticeable in the case of a driver IC with numerous outputs.
Therefore, in view of the problems described above, it is an object of the present invention to provide a semiconductor device that can shorten the length of a driver IC in its short-edge direction, and narrow a frame section of a LCD module to slim down the same.
To solve the problems described above, a semiconductor device in accordance with the present invention pertains to a semiconductor device for supplying a first group of drive signals to a first group of signal electrodes and a second group of drive signals to a second group of signal electrodes of an image display apparatus that displays a two-dimensional image, the semiconductor device comprising: a semiconductor substrate; a first output section that is formed in a first region along a first edge in a longitudinal direction of the semiconductor substrate, and that outputs a specified number of drive signals among the first group of drive signals; a second output section that is formed in a second region along the first edge adjacent to the first region, and that outputs a second group of drive signals; a third output section that is formed in a third region along the first edge adjacent to the second region, and that output the remaining drive signals among the first group of drive signals; a first power supply section that is formed in a fourth region along a second edge in the longitudinal direction of the semiconductor substrate, and that supplies a power to at least the first output section; and a second power supply section that is formed in a fifth region along the second edge, and that supplies a power to at least the third output section.
The embodiment may further be provided with a storage section that is formed in a sixth region between the fourth region and the fifth region along the second edge and that successively stores input image data and supplies the same to the first through third output sections. Also, it may further be provided with a wiring that is formed above the first through third output sections through a dielectric layer for exchanging a potential between the first power supply section and the second power supply section. Furthermore, the image display apparatus may be a liquid crystal display apparatus, the first group of drive signals may be a plurality of common signals that are respectively supplied to a plurality of common electrodes of the liquid crystal display apparatus, and the second group of drive signals may be a plurality of segment signals that are respectively supplied to a plurality of segment electrodes of the liquid crystal display apparatus.
By the invention constructed in a manner described above, the length of a semiconductor device that drives an image display apparatus can be shortened in a short-edge direction of a semiconductor device, and a frame section of an image display module can be narrowed and a slimming-down thereof can be achieved.